Method and apparatus for automated storage and retrieval of miniature shelf keeping units

ABSTRACT

An automated pharmaceutical or biotech compound testing system uses a very small molded plastic shelf keeping unit or test tube known as a “minitube”. The minitubes are stored in trays in a standing refrigeration unit and are retrieved by a machine or robot having a die cutting tubular end effector adapted to selectively cut away and remove a minitube from an integrally molded matrix containing hundreds of minitubes (e.g., 384); the matrix is called a minitube well plate. Upon cutting a selected minitube away from the matrix, the end effector is pushed down over the selected minitube, thus forcing the minitube into the cylindrical interior lumen of the end effector, where it is retained by friction fit until such time as the minitube is to be releaseably locked into a plastic receiving tray. Minitubes are stored in the plastic tray which is adapted to receive and releaseably hold or lock the tubes in place. The minitubes themselves are molded plastic tubes having distally projecting spaced apart “rabbit ear” detent lock members which are biased outwardly. The plastic receiving tray has apertures sized to receive the minitubes and each aperture of the tray is terminated at bottom in a hole defined within chamfered shoulders adapted to slidably engage and exert transverse force against the minitube rabbit ears. The two rabbit ears and the hole together comprise a detent lock system, the minitube rabbit ears releaseably engage the shoulder surfaces on the bottom of the hole in each aperture of the tray. The robot end effector can withdraw and replace the tubes as needed to perform automated testing.

PRIOR APPLICATION INFORMATION

This application claims benefit from co-pending and commonly ownedprovisional patent application No. 60/340,284, which was filed Dec. 13,2001, the entire disclosure of which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to automated chemical, pharmaceutical orbiotech compound testing systems using miniature shelf keeping units ortest tubes. The shelf keeping units or test tubes are preferably storedin a standing refrigeration unit and are retrieved by a robot.

2. Discussion of the Prior Art

In prior art systems, shelf keeping unit parts are separately molded toprovide, for example, an array of 384 miniature shelf keeping units ortest tubes; the tubes are inserted in a matrix of 384 square sockets,thus requiring a very costly assembly.

Industry standards promulgated (in draft form) by the Society forBiomolecular Screening (“SBS”) specify standard dimensions andcharacteristics for microtiter plates (or microplates). The SBS homepageis attached hereto as appendix A; the SBS Microplate StandardsDevelopment Committee'web page printout is attached hereto as appendixB. The SBS Microplate Standards Development Committee draft standardSBS-1 (Footprint Dimensions) is attached hereto as appendix C, and theSBS Microplate Standards Development Committee draft standard SBS-4(Well Positions) is attached hereto as appendix D. Taken together, theseserve to enable a person of ordinary skill in the art to understand thespecifications of the prior art shelf keeping units.

In use, a robotic retrieval system responds to requests whereinindividual tubes are taken from a plate and moved in a process calledreformatting; the tubes are moved to another plate, e.g., having adifferent makeup of compound. In executing a reformatting request for arandom assortment of tubes in many plates throughout the system, onetube can be taken from each plate and put it in another set-up ofplates, ordering the tubes in accordance with the request.

The shelf keeping units or tubes are accessed by pipettes having tipsdimensioned to fit into the tubes, for withdrawing fluid from the tubesor dispensing fluid into the tubes. Scientific Equipment vendors such asGlobe Scientific, Inc. or CCS Packard supply pipette tips adapted foruse with robotic or automated laboratory equipment. An excerpt of the“online catalog” taken from the Globe Scientific, Inc. web sitedescribes tips designed to fit pipettors used in automated testing andis attached hereto as appendix E. Additionally, an excerpt of the“Chemicals and Supplies” information taken from the CCS Packard web sitedescribes “Robotic Certified” pipette tips designed for use with 96 or384 channel pipettors used in automated testing and is attached heretoas appendix F. Taken together, these serve to enable a person ofordinary skill in the art to understand the characteristics of pipettesused in conjunction with industry standard shelf keeping units.

The shelf keeping units or tubes of the prior art must be sealed forstorage and automated handling and reliably sealing each shelf keepingunit is expensive and difficult, since each shelf keeping unit is small.

There is a need, therefore, for an economical and effective automatedpharmaceutical or biotech compound testing system using a very smallshelf keeping unit.

OBJECTS AND SUMMARY OF THE INVENTION

Accordingly, it is a primary object of the present invention to overcomethe above mentioned difficulties by providing an economical andeffective automated pharmaceutical or biotech compound testing systemusing a very small minitube shelf keeping unit.

In accordance with the present invention, an automated pharmaceutical orbiotech compound testing system uses a very small molded plastic shelfkeeping unit or test tube known as a “minitube”. The minitubes arestored in trays in a standing refrigeration unit and are retrieved by amachine or robot having a die cutting tubular end effector adapted toselectively cut away and remove a minitube from an integrally moldedmatrix containing hundreds of minitubes (e.g., 384); the matrix iscalled a minitube well plate. Upon cutting a selected minitube away fromthe matrix, the end effector is pushed down over the selected minitube,thus forcing the minitube into the cylindrical interior lumen of the endeffector, where it is retained by friction fit until such time as theminitube is to be releaseably locked into a plastic receiving tray.

Minitubes are stored in the plastic tray which is adapted to receive andreleaseably hold or lock the tubes in place. The minitubes themselvesare molded plastic tubes having distally projecting spaced apart “rabbitear” detent lock members which are biased outwardly. The plasticreceiving tray has apertures sized to receive the minitubes and eachaperture of the tray is terminated at bottom in a hole defined withinchamfered shoulders adapted to slidably engage and exert transverseforce against the minitube rabbit ears. The two rabbit ears and the holetogether comprise a detent lock system, the minitube rabbit earsreleaseably engage the shoulder surfaces on the bottom of the hole ineach aperture of the tray. The robot end effector can withdraw andreplace the tubes as needed to perform automated testing.

The minitube receiving tray or plate includes spaces aligned in twentyfour columns and rows A through P. That number of minitubes was selectedfor storage because the standard three hundred and eighty four elementwell plate from the Society for Biomolecular Screening (SBS) providesexterior dimensions (e.g., as cited above and described in the attachedappendices). Conformance with the SBS standard was an important goal ofdeveloping the method and apparatus of present invention.

The problem presented was to mold the entire 384 well cassette (alsoreferred to as the minitube well plate or matrix) as one unit, in afunctional unit that doesn't need any further assembly. The minitubewell plate just one piece, once out of the mold, already in a shapecompatible with the format called the SBS Plate or the 384 well plate,so it's ready to use as-is, coming out of the mold.

In use, the individual minitubes are periodically taken out and“reformatted” into another plate, e.g., having a different makeup ofcompound in the minitubes. A receiving tray may include, for example arandom assortment in the 384 well plates throughout the system and auser may need to pick one out of each of these plates and put it inanother entire set-up of plates, ordering them for the request. Inresponse to the request, the minitubes are punched out of a minitubewell plate with the die end effector and placed in a receiving plate insuch a wav that the minitube can be used in the laboratory. The minitubecannot be laid loosely in the plate aperture, instead, each minitube hasto be pressed in and releaseably locked in or retained such that itwon't come back out until selectively removed using the robot endeffector.

The molded matrix structure including the minitubes molded integrallywith the holder is referred to as the minitube well plate. The volume ofeach minitube is about sixty microlitres, and the exterior dimensions ofeach minitube are optimized to conform to the SBS spacing standard fordimensions a 384 tube well plate. The minitube design provides thelargest volume that's functional in that format and size. Within the SBSstandard format, the tube structure provides maximum usable volume. Eachminitube has a rounded or pointed bottom, so that the pipette can reachclose to the bottom, and get almost all of the material out. There are alarge number of standard pipettes that are available. A cross-section ofpipettes was studied to ensure they could fit down to the bottom easilywithout hitting the side. Well known pipette companies include Tecan,Becton-Dickenson, and Perkin Elmer.

Returning to the minitube well plate, the top surface is substantiallyplanar and all of the minitubes are arranged in an evenly spaced patternin a two dimensional array, in substantial conformance with the abovecited SBS “well positions” draft standard, SBS-4. The minitube wellplate shares of the present invention certain characteristics withstandard (sBS-4) plate, but differs in the minitube configuration asseen from the bottom and in that the minitubes are integrally moldedinto the plate structure.

The top of the minitube well plate is planar upper surface which permitsan operation covering all of the minitubes at once. On that planar topsurface, and around each circular hole defining the minitube openings,where the minitube is molded in, there is a small annular ridge aroundeach hole—one can feel the ridge with a fingernail. The annular ridge israised and is used for heat sealing; a foil sheet with a polymer back isused to seal all the minitubes at once. The polymer layer melts to thepolymer on the minitube well plate ridge, this independently sealingeach tube at the annular ridge. The first point of contact is thatlittle ridge around each well or minitube interior whereby each tube iscompletely sealed. Each minitube remains sealed after it's been cut andreleased by the die cutter and holder:

The preferred “membrane material” for affixing that sealing cover is acommercially available aluminum foil having a polymer coating on theback. The polymer coating may be polypropylene or polyethylene.

When attaching the foil to the minitube well plate, even heat andpressure is applied over the entire top surface using a pair of platens.A smooth top platen on the top surface and a platen underneath havingholes cut out for each of the (e.g., 384) tubes so that the actual pointof contact of the bottom platen is right at the top of the minitube wellplate inner wall. Thus, when closed in the heat sealing operation, thetwo platens are essentially about a sixteenth of an inch apart, a spancorresponding to the thickness of the minitube well plate top wallsegment. During sealing, the bottom platen comes into intimate contactwith the underside of the minitube well plate, and so acts essentiallylike a female mold, adapted to receive it the underside of the minitubewell plate completely, whereas the top platen is just a flat rectangularpiece that is slightly larger in area than the minitube well plateplanar top surface.

During the heat sealing process, the minitube well plates are supportedat the very bottom of the plate while the platen on top pushes down, soa very uniform pressure is applied, thereby achieving, among otherthings, enhanced reliability in the sealing of individual tubes.

Returning to the annular sealing ridge, the ridge is substantiallytriangular in cross section. This ridge shape is suitable for ultrasonicsealing as well as heat sealing and there's a pretty wide and forgivingrange of ridge shape to present on a high spot to take the pressurefirst and achieve that melt. The melt must bond the sealing membranecompletely around the circumference of the minitube and it is importantthat the bond that is created not be undone when the die cutter reachesin and cuts the minitube out of the well plate.

The die cutter shape or dimensions are dictated in part by that goal.Particularly, the die cutter has an angled edge, e.g., 20 degrees to theinside, whereby a knife-like beveled edge is presented. That bevelededge is very sharp, from a design tradeoff perspective, the balance isbetween having a shallower angle (rendering cleaner cut) or a largerangle (rendering longer wear, for longevity). At present, the priorityis functionally making clean cuts, so the individual minitube seals arereliably left intact after the cutting step has taken place. A sharpcutting edge also helps maintain the flatness of that planar surface,over the whole plate, during the removal of all the tubes. The removalprocess is usually random in that tubes are removed at one point andthen another and another. The typical completely random request processfor the chemicals in these tubes might have three or four tubesremaining right in the middle after everything else is punched outaround them, and a relatively flat well-oriented web must be maintainedto hold those tubes. Another advantage of a very sharp cutting bevelededge is that, in use, the minitube well plate remains substantiallyplanar as the tubes are cut out.

The minitube itself is tapered from top to bottom, having a gentlydecreasing diameter from top to bottom and being circular incross-section. The die cutter has an interior defining a straightcylinder. The cutting edge is on the outside of the cylinder, and theoutside is tapered for strength. The die cutter body also has a taper atthe top that creates the beveled knife edge. There is a dual taperthere; a two degree taper mirroring the minitube sidewall, so theadjacent minitubes allow for a two degree outward taper on the die. Theminitube uses every bit of material that will fit within the clearancesdefined by adjacent placements of the die cutter. The die cutter tapergives enhanced tool strength and the tapered area around each minitubeallows for that clearance and allows the die cutter to have that taperoutward.

The above and still further objects, features and advantages of thepresent invention will become apparent upon consideration of thefollowing detailed description of a specific embodiment thereof,particularly when taken in conjunction with the accompanying drawings,wherein like reference numerals in the various figures are utilized todesignate like components.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the entire automated retrieval system,in accordance with the present invention.

FIG. 2 is a cross sectional view of the robot end effector and receivingplate, with a locked-in minitube, in accordance with the presentinvention.

FIG. 3 is a perspective view of the minitube well plate or matrix andthe die cutter end effector, in accordance with the present invention.

FIG. 4 is a front view, in elevation, of the minitube automatedretrieval robot system, in accordance with the present invention.

FIG. 5 is a perspective view of the minitube automated retrieval robotsystem, in accordance with the present invention.

FIG. 6 is a perspective view of the minitube automated retrieval robotsystem, in accordance with the present invention.

FIG. 7 is a perspective view of an individual minitube shelf keepingunit, in accordance with the present invention.

FIG. 8 is a perspective view of the minitube automated retrieval robotsystem, in accordance with the present invention.

FIG. 9 is a cross sectional perspective view of the robot end effector,minitube and receiving plate, in accordance with the present invention.

FIG. 10 is a close-up cross sectional perspective view of the robot endeffector, minitube and receiving plate, in accordance with the presentinvention.

FIG. 11 is a cross sectional view of the minitube receiving plate withminitubes locked in place therein, in accordance with the presentinvention.

FIG. 12 is a line drawing, in elevation, of an individual minitube shelfkeeping unit illustrating the sealing annular ridge, in accordance withthe present invention.

FIG. 13 is a cross sectional view of a minitube well plate and diecutting end effector in position to cut away a selected sealedindividual minitube shelf keeping unit, in accordance with the presentinvention.

FIG. 14 is a cross sectional view of a minitube well plate and diecutting end effector in position to cut away a selected individualminitube shelf keeping unit, in accordance with the present invention.

FIG. 15 is an enlarged cross sectional perspective view of the robot endeffector, minitube and receiving plate of FIG. 9, in accordance with thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIGS. 1-15, in accordance with the present invention,an automated miniature shelf keeping unit storage and retrieval system20 uses a very small molded plastic shelf keeping unit or test tubeknown as a “minitube” 22. The minitubes 22 are stored in trays in(preferably) a standing refrigeration unit and are retrieved by amachine or robot 24 having a die cutting tubular end effector 26 adaptedto selectively cut away and remove a minitube 22 from an integrallymolded matrix 28 containing hundreds of minitubes (e.g., 384). Thematrix is also called a minitube well plate 28 and preferably includes asealing membrane or layer covering the upward facing openings of theminitubes. Upon cutting a selected minitube 22 away from the matrix, theend effector 26 is pushed over the selected minitube, thus forcing theminitube into the cylindrical interior lumen of the end effector 26,where it is retained by friction fit until such time as the minitube isto be releaseably locked into a plastic minitube receiving tray or plate30.

Minitubes are stored and moved from place to place in the receivingplate 30 which is adapted to receive and releaseably hold or lock thetubes in place. As best seen in FIGS. 2, 7 and 12, minitube 22 is amolded plastic tube having distally projecting spaced apart “rabbit ear”detent lock members 32, 34 which are biased transversely or outwardly.The plastic receiving tray has apertures sized to receive the minitubesand each aperture of the tray is terminated at bottom in a hole 36defined within chamfered shoulders adapted to slidably engage and exerttransverse force against the minitube rabbit ears 32, 34. The rabbitears 32, 34 and the hole 36 together comprise a detent lock system. Theminitube rabbit ears releaseably engage the shoulder surfaces on thebottom of the hole in each aperture of the receiving plate or tray 30.The robot end effector 26 can withdraw and replace the tubes 22 asneeded to perform automated testing.

The minitube receiving tray or plate 30 includes spaces aligned intwenty four columns and rows A through P. That number of minitubes 22was selected for storage because the standard three hundred and eightyfour element well plate from the Society for Biomolecular Screening(SBS) provides exterior dimensions (e.g., as cited above and describedin the attached appendices). Conformance with the SBS standard was animportant goal of developing the method and apparatus of presentinvention.

The problem presented was to mold the entire 384 well cassette (alsoreferred to as the minitube well plate or matrix 28) as one unit, in afunctional unit that doesn't need any further assembly. The minitubewell plate, once out of the mold, is already in a shape compatible withthe format called the SBS Plate or the 384 well plate, so it's ready touse as-is, coming out of the mold (not shown).

In use, the individual minitubes 22 are periodically taken out and“reformatted” into another plate 30, e.g., having a different makeup ofcompound in the minitubes. A receiving plate 30 may include, for examplea random assortment in the 384 well plates throughout the system and auser may need to pick one out of each of these plates and put it inanother entire set-up of plates, ordering them for the request. Inresponse to the request, the minitubes 22 are punched out of a minitubewell plate 28 with the die end effector 26 and placed in a receivingplate 30 in such a way that the minitube can be used in the laboratory.The minitube 22 cannot be laid loosely in the plate aperture, instead,each minitube has to be pressed in and releaseably locked in or retainedsuch that it won't come back out until selectively removed using therobot end effector 26.

Minitube well plate 28 comprises a molded matrix structure including theminitubes 22 molded integrally with the holder. The volume of eachminitube 22 is preferably about sixty microlitres, and the exteriordimensions of each minitube illustrated in FIG. 12 and are optimized toconform to the SBS spacing standard for dimensions a 384 tube wellplate. The minitube design provides the largest volume that's functionalin that format and size. Within the SBS standard format, the tubestructure provides maximum usable volume. Each minitube 22 has a roundedor pointed bottom, so that the pipette can reach close to the bottom,and get almost all of the material out. There are a large number ofstandard pipettes that are available. Across-section of pipettes wasstudied to ensure they could fit down to the bottom easily withouthitting the side. Well known pipette companies include Tecan,Becton-Dickenson, and Perkin Elmer.

Returning to minitube well plate 28, the top surface 38 is substantiallyplanar and all of the minitubes 22 are arranged in an evenly spacedpattern in a two dimensional array, in substantial conformance with theabove cited SBS “well positions” draft standard, SBS-4. The minitubewell plate of the present invention shares certain characteristics withstandard (SBS-4) plate, but differs in the minitube configuration asseen from the bottom in that the minitubes are integrally molded intothe plate structure.

The planar top or upper surface 38 which permits an operation coveringall of the minitubes at once. On that planar top surface 38, and aroundeach circular hole defining the minitube openings, where the minitube ismolded in, there is a small annular ridge 40 around each hole—one canfeel ridge 40 with a fingernail. Annular ridge 40, best seen in FIG. 12,is raised and is used for heat sealing. A foil sheet with a polymer backis used to seal all the minitubes in the well plate 28 at once. The foilsheet polymer layer melts to the polymer on the minitube well plateridge 40, thus independently sealing each tube at the annular ridge. Thepoint of contact is the little ridge around each well or minitubeinterior and so each tube 22 is completely sealed. Each minitube 22remains sealed after it's been cut and released by the die cutter/holderend effector 26.

The preferred “membrane material” for affixing the sealing cover is acommercially available aluminum foil having a polymer coating on theback. The polymer coating may be polypropylene or polyethylene.

When attaching the foil to the minitube well plate 28, even heat andpressure is applied over the entire top surface using a pair of platens(not shown). A smooth top platen on the top surface and a platenunderneath having holes cut out for each of the (e.g., 384) tubes 22 sothat the actual point of contact of the bottom platen is right at thetop of the minitube well plate inner wall. Thus, when closed in the heatsealing operation, the two platens are essentially about a sixteenth ofan inch apart, a span corresponding to the thickness of the minitubewell plate top wall segment. During sealing, the bottom platen comesinto intimate contact with the underside of the minitube well plate 28,and so acts essentially like a female mold, adapted to receive it theunderside of the minitube well plate completely, whereas the top platenis just a flat rectangular piece that is slightly larger in area thanthe minitube well plate planar top surface 38.

During the heat sealing process, the minitube well plates 28 aresupported at the very bottom of the plate while the platen on top pushesdown, so a very uniform pressure is applied, thereby achieving, amongother things, enhanced reliability in the sealing of individual tubes22.

Returning to the annular sealing ridge 40, and referring to FIG. 12which shows the ridge (diameter of 0.122″); it is substantiallytriangular in cross section (and has a height of 0.009″). In fact, thereare many useful sealing methods, this ridge shape has been used forultrasonic sealing as well as heat sealing and there's a pretty wide andforgiving range of ridge shape to present a high spot to take thepressure first and achieve the desired sealing melt. The melt must bondthe sealing membrane completely around the circumference of the minitubeand it is important that the bond that is created not be undone when thedie cutter reaches in and cuts the minitube out of the well plate.

The die cutter shape or dimensions (of end effector 26) are dictated inpart by the goal or reliable sealing. Particularly, the die cutter hasan angled edge, e.g., 20 degrees to the inside, whereby a knife-likebeveled edge is presented. Referring to FIGS. 13-15 and FIG. 9, thebeveled edge is preferably very sharp; the balance is between having ashallower angle (rendering cleaner cut) or a larger angle (renderinglonger wear), for longevity. At present, the priority is functionallymaking clean cuts, so the seals are reliably intact after the cuttingstep has taken place. A sharp cutting edge also helps maintain theflatness of planar surface 38, over the whole plate, during the removalof all the tubes. The removal process is usually random in that tubes 22are removed at one point and then another and another. The typicalcompletely random request process for the chemicals in these tubes mighthave three or four tubes remaining right in the middle of matrix 28after everything else is punched out around them, and a relatively flatwell-oriented web must be maintained to hold those few tubes. That'sanother reason why a very sharp cutting beveled edge is required, sothat the minitube well plate top surface 38 remains substantially planaras the tubes 22 are cut out.

As best seen in FIGS. 7 and 12, minitube 22 is tapered from top tobottom, having a gently decreasing diameter from top to bottom and beingcircular in cross-section. The die cutter of end effector 26, as bestseen in FIGS. 13-15, has an interior defining a straight cylindricallumen. The end effector cutting edge is on the outside of the cylinder,and the outside is tapered for strength. The die cutter body also has ataper at the top (best seen in FIG. 13) that creates the beveled knifeedge. There is a dual taper there; a two degree taper mirroring theminitube taper, so the adjacent minitubes allow for a two degree outwardtaper on the end effector cutting die. The minitube 22 uses every bit ofmaterial that will fit within the clearances defined by adjacentplacements of the die cutter. The die cutter taper gives more toolstrength and the tapered area around each minitube allows for thatclearance and allows the die cutter to have that taper outward.

Turning now to some additional details of the minitube invention, theshape of the rabbit ears and the method of putting a minitube in theholding tray and withdrawing are important novel elements of theinvention. The prior art, by comparison, involves much greater cost,because separately molding 384 little tiny tubes and inserting them in amatrix of 384 little square sockets is a very costly assembly. Thepresent invention, by way of contrast, replaces that assembly withsomething less expensive; the method of the present invention includesmolding the entire 384 well cassette as one unit, in a functional unitthat doesn't need any further assembly. It's just one piece, one out ofthe mold, already in the format of the SBS Plate, or the 384 well plate,so it's ready to use as-is, coming out of the mold. Now that's all welland good but what needs to happen from there is these individual tubesneed to be taken out and reformatted into another plate having adifferent makeup of compound (whatever the compounds are in those littletubes). It might be, a random assortment in the 384 well platesthroughout the system and the user may need to pick one out of each ofthese plates and put it in another entire set-up of plates, such thatthere's an order to them now for this request. And so, in the method ofthe present invention, the molded-in minitubes are punched out andplaced in such a way that they can be used in the laboratory. Theminitubes can't just be laid in there, they have to be pressed in, insuch a way that the minitubes won't come back out. And thats why theminitubes have ears which are received in the receiving tray holes. Thelittle ears or detents, when they're pressed in, they snap into placeand then hot or cold, warm or cold, it doesn't really matter becausethey're now retained, and snapped into place.

Referring now to the refrigerated storage, the pick and place roboticequipment is novel and more efficient as a result of this minitubestructure. The robotic equipment is called an end effector, and isessentially a punching unit that has a punch and a die set up. The punchis a two stroke set-up that, in the first part of the stroke or thefirst stroke, is used to actually shear the tube out of the moldedmatrix. The minitube is retained by friction in the die and then thewhole unit goes over to the receiving cassette or tray and then thesecond stroke is all the way through the die, the punch goes all the waythrough the die down to the bottom and presses the minitube into placein the receiving cassette or tray. Once that minitube is put into thereceiving cassette, it can actually be extracted from that receivingcassette and put into another receiving cassette, which allows what iscalled compression, meaning one can take out the remaining tubes in awell plate—e.g., if one has 384 to start and over a period of, say, sixmonths 350 are taken out, then 34 are left, one can punch those 34 outand place them in a receiving cassette. In addition, the user canextract minitubes out of the receiving tray; instead of punching themout, the system includes a little extractive tool or pin that pushes upfrom the bottom through the receiver cassette ear-retaining hole andactually replaces that tube inside the die of the punch and die, afeature shown in cross section in the drawings.

Having described preferred embodiments of a new and improved method,apparatus and system it is believed that other modifications, variationsand changes will be suggested to those skilled in the art in view of theteachings set forth herein. It is therefore to be understood that allsuch variations, modifications and changes are believed to fall withinthe scope of the present invention as defined in the claims.

1. Apparatus for automated storage and retrieval of miniature shelfkeeping units, comprising: a substantially planar molded tray includinga plurality of integrally molded tube structures, each of said tubestructures having a selected outside diameter, said tray having an uppersurface and a plurality of side walls carried in a substantiallyperpendicular orientation with respect to said upper surface; each ofsaid integrally molded tube structures defining a hollow cavityterminated at a distal end in a closed, fluid tight boundary andterminated at a proximal end in an opening in fluid communication withsaid tube hollow cavity, said tube proximal end openings being alignedin a plane that is substantially co-planar with said tray upper surface.2. The apparatus of claim 1, wherein said tube structure distal endscarry first and second resilient, spaced, biased detent lock membersprojecting distally therefrom.